Question 18M.2.SL.TZ1.c
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.2.SL.TZ1.c |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Distinguish | Question number | c | Adapted from | N/A |
The land snail Cepaea nemoralis is very common in North America and in Europe.
The base colour of its shell varies between brown, pink and yellow, and also in its intensity. Some shells are unbanded, but most show one to five bands of different width on top of the shell base colour.
In the early 1950s, scientists studied the proportion of colours and banding of C. nemoralis in woods and fields near Oxford, UK, which differed in the type of plants and background colour. Each data point on the graph represents the percentage of yellow base colour shells and unbanded shells in a sample from either one type of wood or field, although other snail colours were present.
Using the data in the graph, distinguish between the distribution of C. nemoralis shells in woods and fields.
[2]
a. more yellow in fields (than in woods) / vice versa
b. more unbanded in woods (than in fields) / vice versa
c. more overlap within banding than within yellow colour
OR
yellow colour range greater than banding range
d. very little overlap between fields and woods / some outliers
Do not accept answers with only numerical data.
